The inventive concept relates to light emitting diodes and light emitting diode packages and, more particularly, to light emitting diodes capable of improving a current diffusion characteristic and light emitting diode packages including the same.
A light emitting diode (LED) is a type of P-N junction diode. The light emitting diode is a semiconductor device using an electroluminescence that monochromatic light is emitted when a forward bias is applied thereto. A wavelength of the light emitted from the light emitting diode may be determined depending on bandgap energy (Eg) of a material used for the light emitting diode. Light emitting diodes emitting infrared rays and a red light were mainly developed in the initial stages of light emitting diode techniques. In 1993, Nakamura of Nichia chemical industries discovered that a blue light was generated using gallium nitride (GaN). After that, blue light emitting diodes have been developed. A white color is made by mixing a red color, a green color, and blue color. Thus, the blue light emitting diode based on the gallium nitride (GaN) and previously developed red and green light emitting diode may enable a white light emitting diode to be realized.
Meanwhile, light-emitting efficiency and a lifetime of light emitting diode should be improved for increasing marketability thereof. However, in the blue light emitting diode based on the gallium nitride, light generated in an active layer may be partially outputted from the blue light emitting diode by difference between refractive indexes of the gallium nitride and air, and the generated light may be mostly re-absorbed in the blue light emitting diode to become extinct. Thus, almost of blue light emitting diodes have low light-emitting efficiencies of about 4%. Recently, various techniques are suggested for increasing the light-emitting efficiency.